I was wondering if the following troubleshooting steps could be added to FAQ 211 (but worded much better and more detailed as needed, LOL):
Making sure that they typed their username correctly, as well. What sometimes happens (and more frequently than you'd think) is that someone misremembers the exact spelling of their username and inadvertently enters a different registered username. When that happens, they'll get the "invalid password" error message.
If the user has their browser's "auto-complete" function enabled, that could interfere with the information they try to manually enter into the password field.
If the user makes use of their browser's "password manager" feature, that could also interfere, especially if they changed their LiveJournal password but have not updated that information in their password manager.
As always, thanks in advance for considering these. =)